Pole scaffold



NOV. 17, 1936. A, STRQM A 2,060,953

` POLE SCAFFOLD Filed Nov. 25, 1935 3 Sheets-Sheet l Invenlor a7 of ffa/ff A llorney Nov. 17, 1936.

A, STROM POLE scAFFoLD l Filed Nov. 25, 1935 5 Sheets-Sheet 2 EMI 7/ C) f 2f `72 Inventor af/ of ff/0777 A Homey Nov. 17, 1936. A. sTRoM POLE scAFFoLD Filed Nov. 25, 1935 5 Sheets-Sheet 5 nUenlor /jo 7L ,ff/W27 Alforney Patented Nov. 17, 1936 PATENT GFFICE POLE SCAFFOLD4 Algot Strom, Juneau, Alaska, assgnor of'one-half to J. ArchBulger, Juneau, Alaska Application November 25, 1935, SerialA No. 51,509

Claims.

This invention. relates to pole scaifolds.

The primary object of the present invention is to provideL a scafloldadaptable to be detachablyengaged to roundfsteel or wooden poles by 5' a pairl of pole encircling chains, the upper chain producing a-self-tightening effect as weight is applied to the platform or scaffold.

Another feature of the present invention is a chainv tightening mechanism carried by the frame ofthe scaffold vWhichpermits one of the chainsI to be' tightened or loosened at will.

Further objects of the invention are to provide a device Vofthe character referred to that is strong, compact and durable, thoroughly reliablefor each intended purpose, very easy to attach'fand detach'from a pole and that is comparatively inexpensive to manufacture. vWith the foregoing and other objects in view the invention consists of a novel construction, combination and arrangement of parts as Will be' hereinafter more specifically described and illustrated rin 'the accompanying drawings,

wherein is disclosed an embodiment of the inventin,- but it is to be understood that changes, variations andgmodilications may be resorted to without departing from the spirit of the claims hereunto appended. K

In the drawings wherein like reference characters;` denote corresponding parts throughout the several-views:- vFigure 1 is a fragmentary elevation of a portion of-a poleshowing an adaptation therewith of the device in accordance with the present invention'and having parts of the device broken aways' l VFigure-'2 is a top plan view of the device partly broken away and removed from the pole.

Figure 3 is a vertical section through the frame ofthe device taken substantially on the planefof line 43 7-3 of Figure 2.

Figure, 4-is a front elevation of the frame.

Figure 5' is a rear elevation of the frame.

Figure '6 is an enlarged fragmentary side elevation of the frame and an axial detailed sectionythrough the chain adjusting means.

Figure r7 is a detailed diametric section taken substantiallyl on the plane of line 'l-l of Fig- (Cl. 304-28)v steel.` 'Ihe frame A is formed of a pair of companion side rails I0, II which extend in spaced parallel relation.v

The lowerends of the side rails merge with an outwardlyvbowed bottom rail I2. The upper ends of the side rails IIJ, I I are curved outwardly as indicated at I3 and particularly shown in Figure 3V of the drawings. On the outside of the curved portion I3 of the rail ID is an anchoring cleat I4, while'there is a like cleat I5 on side rail II in alignment with cleat I4. On the confronting faces of the jaws of the cleats I4, I5 are gripping ribs I6 which ribs anchor between the links on the opposite end portions of the upper or safety chain I "I, and the intermediate portion. of the chain encircles and grips the pole. 'The casting of the frame A is further formed with an arched member indicated generally at I8 which bridges an intermediate portion of the side rails nearly in the center thereof. This arch member I8 is bowed outwardly so that the inner face thereof has gripping engagement with a segment of the circumference of a pole. There is a dove-tailed pocket I9 on the inner face of the arch member which extends from the upper edge substantially one half of the Width thereof. In this pocket I9 fits a plate 20 that permits the frame to be attached to a right-angled object, construction, or position. On each side of the pocket I9 are spaced vertically extending parallel ribs 2|, 22 and between the parallel ribs and the pocket I9 are curved ribs 23. The curved ribs or corrugations prevent downward slipping, of the frame A, while the vertical parallell ribs prevent side slipping on either steel or wooden poles. In each rail I0, II extending from the inner edge thereof are Wooden spurs 24 that detachably seat in sockets 25 formed in the rails.

Extending rearwardly from the rear face of the arch member I8 of the frame are a pair of spaced bars 26, 21. 'Ihe space between the bars 26, 21 provides a pocket to receive the inner end of the scaffold board or platform board 28 and this board is secured to the bars by means of the bolts 29.

On an intermediate portion of one side rail I0 and on the outside thereof is a cleat 30. This cleat 30 is similar in all respects to the cleats I4, I5 and has ribs on the confronting faces of the jaws thereof which engage between the links at the one end of the lower or binding chain 3I. The binding chain 3| is adjustable to tighten or loosen the same from pole encircling relation and for' this purpose there are a pair of horizontally spaced bosses 32, 33 on the outside of rail II in alignment with the arch member I8. In each lug is a smooth bore which is aligned with the other. There is a bolt 34 coupled to the one end of the lower or binding chain 3| as at 35. The threaded shank 36 of the bolt 34 extends through the smooth bores in bosses 32, 33 in slidable relation and on an intermediate portion of the threaded shank is threadably engaged an annular ratchet member 31. Around the center of the outer periphery of the ratchet member 31 are the continuous series of ratchet teeth 38. To operate the ratchet member 31 and screw the bolt 34 in or out for tightening the binding chain 3I is a ring 39 rotatably mounted on the smooth outer margins of the ratchet member 31. `Around the center on the inside periphery of member 39 is an annular cavity 40 and the teeth 38 are free to move in this cavity. In one side of the cavity 40 is an inset recess 4I and in this recess 4I is pivoted a forked ratchet dog having opposed prongs 42, 43. One or the other of the prongs engages the teeth 38 depending upon whether bolt 34 is tightening or loosening chain 3I. So as to permit the dog to rock, the center is fixed to a pivot 44 journaled in the opposite side Walls of the cavity 4 I. Merging with the cavity 4 I `is a pocket 45 and in this pocket is a helical overcenter spring 46. The outer end of this coil spring 46 bears against the wall of the pocket 45 and the inner end thereof embraces a lug on the outside of the ratchet Idog at a point in alignment with the pivot 44 so that when either one or the other of the prongs are engaged with ratchet teeth the spring holds the same engaged, because in engaged position the axis of the spring is disposed at an angle. This construction of the forked dog with the pivot and spring arrangement permits a ratchet movement when tightening the binding chain 3I, or when the binding chain 3| is being loosened. From the outer periphery of the ring member 39 extends the operating handle 41. One end of pivot pin 44 has a crank 44a that extends on the outside of the ring member 39 and moves in a pocket 44h. By swinging crank 44a to either end of its arc either one or the other of the prongs on the ratchet dog are brought into engagement with teeth 38 where they are retained in the engaged relation by the spring 46.

In attaching the device of the present invention to a pole the safety chain I1 is attached rst. So as to obtain a tight fit about the pole the frame is rocked inwardly on the curved portion I3 of the side rails. By rocking the frame inwardly a tight t is accomplished when the links are slipped into the upper cleats l5, I6. Then the lower or binding chain 3| is attached by slipping the link on the free end of the binding chain into the cleat 30. Thisv being done, handle 41 is turned whereupon the bolt moves outwardly thereby tightening the binding chain 3| and bringing the frame into tight gripping relation with a portion of the periphery of the pole. The chains I1 and 3I encircle the pole in parallel relation. To remove the device handle 41 is turned so that the bolt moves inwardly and when the binding chain 3l is loose the links may be slipped from the cleat 30. The upper chain I1 may then be removed from the engaging cleats I4, I5.

Having described my invention, what I claim 1. In combination with a pole scaffold Characterized by a pole embracing frame a scaffold board carried by the frame, and a pole encircling chain carried by the frame of means for adjusting one end of the chain comprising a pair of spaced apertured bosses carried by the frame, a bolt connected to one end of the chain and having a threaded shank slidable in bosses, a ratchet gear formed with smooth portions on the margin of the periphery with teeth in between and threadedly mounted on an intermediate portion of the shank between the bosses, an operating member formed of a ring slidable on the smooth portions of the ratchet 'gear having a handle extending from the ring, and a rockable ratchet dog in the ring.

2. In combination with a pole scaffold characterized by a pole embracing frame a scaiold board carried by the frame, and a pole encircling chain carried by the frame of means for adjusting one end of the chain comprising a pair of spaced Vapertured bosses carried by the frame, a bolt connected to one end of the chain and having a threaded shank slidable in the said bosses, a ratchet gear formed with teeth in the center and smooth portions on the margins of the periphery and threadedly mounted on an intermediate portion of the shank between the bosses, an operating member formed of a ring slidable on the smooth portions of the ratchet gear having a handle extending from the ring, a rockable ratchet dog in the ring, and said ratchet dog being forked and having a pair of oppositely extending prongs one of which is engaged with the ratchet teeth while the other is free.

3. A pole scaiold, and in combination, a frame for bearing contact with a portion of the periphery of a pole only, said frame equipped with elongated parallel side rails having bearing contact in an axial direction on the pole, an arch member connecting intermediate portions of the rails and having bearing contact in a circumferential direction on a segment of the pole between the side rails, means carried solely by the arch member for anchoring platform boards to the frame, said side rails having portions at one end curved outwardly to provide a fulcrum to rock the curved ends of the rails inwardly, cleats carried by the rails situated at the curved end of the rail so that rocking movement will change the length of an arc between the curved ends, and a chain detachably seated in the cleats and girdling the remaining portions of the pole whereby the scaffold is secured to the pole.

4. A pole scaffold, and in combination, a frame for bearing contact with a portion of the periphery of a pole only, said frame equipped with elongated parallel side rails having bearing contact in an axial direction on the pole, an arch member connecting intermediate portions of the rails and having bearing contact in a circumferential direction on a segment of the pole between the side rails, means carried solely by the arch member for anchoring platform boards to the frame, said side rails having portions at one end curved outwardly to provide a fulcrum to rock the curved ends of the rails inwardly, cleats carried by the rails situated at the curved end 4of the rail so that rocking movement Will change the length of an arc between the curved ends, a chain detachably seated in the cleats and girdling the remaining portions of the pole whereby the scaiTold is secured to the pole, a second pole girdling chain, and means carried by intermediate portions of the side rails for attaching the second chain to the frame.

5. A pole scalold, and in combination, a frame for bearing contact with a portion of the periphery of a pole only, said frame equipped with elongated parallel side rails having bearing contact in an axial direction on the pole, an arch member connecting intermediate portions of the rails and having bearing contact in a circumferential direction on a. segment of the po'le between the side rails, means carried solely by the arch member for anchoring platform boards to the frame, said side rails having portions at one end curved outwardlyto provide a fulcrum to rock the curved ends of the rails inwardly, cleats carried by the rails situated at the curved end of the rail so that rocking movement will change the length of an are between the curved ends, a chain detachably seated in the cleats and girf dling the remaining portions of the pole whereby the scaffold is secured to the pole, a second pole girdling chain, means carried by intermediate portions of the side rails for attaching the second chain to the frame, and said attaching means being adjustable.

ALGOT STROM- 

